Entre Ciel et Terre : les fonctions de l’astronomie dans la Russie du 18^e siècle

This article aims at describing the state and society expectations about astronomy in 18^th century Russia. It starts with Peter I’s attempt to create a powerful navy and to dispose of good maps of his empire, a policy that established a favorable context for the development of practical astronomy. A further step was reached in 1726-27 with the creation of the Academic Observatory and the recruitment of Joseph Nicolas Delisle, whose research program included the movements of stars, the aberration of light, the nutation of the Earth’s axis and atmospheric refractions as well as the determination of longitudes on Earth. His monitoring and organization skills allowed him to mobilize human and material resources beyond the limited circle of specialists. A further favorable circumstance was the presence of Euler, who could develop celestial mechanics on the basis of observations provided by Delisle and his team. Despite ups and downs in the state support, a first peak was reached in 1769, when no less than seven “Russian” teams were organized for observing the Transit of Venus. At Euler’s death (1783), the practice of astronomy had reached such a momentum within the Petersburg academy that it would survive the subsequent reconfiguration of the discipline.